Snow removal equipment



March 23, 1965 LA ROY A. WILSON SNOW REMOVAL EQUIPMENT 2 Sheets-Sheet 1 Filed June 12, 1963 INVENT OR. LA ROY A. WILSON ATTORNEY.

March 23, 1965 LA ROY A. WILSON 3,174,477

.sNow REMOVAL EQUIPMENT Filed June 12, 1965 2 Sheets-Sheet 2 FIG.3.

INVENT OR. LA ROY A. WILSON ATTORNEY.

United States Patent 3,174,477 SNOW REMOVAL EQUHPMENT La Roy A. Wilson, 9641 Accord Drive, Bethesda 14, Md. Filed June 12, 1963, fier. No. 287,450 14- Claims. ((13. 126-2712) (Granted under Title 35, (lode (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to equipment for use in the removal of snow from streets, sidewalks, parking areas. and the like and more specifically to apparatus for removing snow which utilizes heated air to melt the snow.

Previous methods of snow removal have employed blade-type plows or rotary plows, chemical applications, or manual labor and dump trucks. There were, however, numerous disadvantages with these methods, the most significant of which are that they are too time consuming for the eiiicient removal of snow and they are, for the most part, expensive and inetficient in operation. The application of chemicals removes snow very slowly and causes untold damage to street surfaces and to vehicles operated over the surfaces after the chemicals are used. Manual labor and dump trucks are obviously impractical for the reason that this method is too slow and too expensive.

Previous apparatus for snow removal which have utilized heated air to melt the snow have largely been of bulky construction and ineflicient in operation.

It is therefore a primary object of the present invention to provide a new and improved apparatus of the character described.

It is another object to provide snow removal equipment in which a continuous flow of heated air is utilized to efficiently melt the snow.

It is a further object to provide snow removal equipment of the character described which is mobile, compact and safe to use.

It is still a further object to provide a novel fuel burner assembly as the air heating means of snow removal apparatus wherein the percentage of fuel combustion and efiiciency of operation is increased over prior art burner assemblies.

It is another object to provide a fuel burner assembly in combination with an air blower and mounting arrangement therefor wherein the pressure and velocity of flame emanating from said burner is augmented by said air from the blower to give increased pressure and velocity and better heat distribution in the output of the snow melting apparatus.

It is yet another object to provide an improved, compact .fuel burner arrangement adapted to fit a housing or basket of simple design whereby even distribution of flame, air

and temperature may be effected.

It is a further object to provide a gasoline engine as the driving means for the blower assembly and a gas burner as the air heating means which may be easily dismantled for cleaning or replacement of parts.

Other objects and various further features of novelty .and invention will be apparent to those skilled in the art FIG. 3 is an enlarged sectional view of the burner assembly employed in both the mobile and portable snow removal equipment of FIGS. 1 and 2, respectively;

FIG. 4 is a sectional view taken along lines 3-3 of FIG. 3; and

FIG. 5 is a side elevation of the heater housing, partly in section.

Referring to FIG. 1 there is shown at 10 a supporting frame carried by wheels 11 and having attached thereto a handle 20 of any desired shape. At one end of the supporting frame 10 there is mounted in a vertical position a propane supply tank 19 having an outlet 21 in the lower end thereof connected to the propane supply hose or fuel line 22 to the burner assembly 24 located within the burner basket or heater housing 14. A needle valve 23 is placed in the end of the propane supply hose 22 adjacent the heater housing 14 to control the liquid propane flow to the burner assembly.

A gasoline engine 12 is also mounted on supporting frame 10 and has a horizontal drive shaft thereon for driving the belt 16 connected to the drive shaft 15 of the compressor or air blower 13. The compressor or air blower 13 is mounted on a support frame 18 positioned at one of the supporting frame 10. The supporting frame 18 carries the blower 13 at approximately degrees with respect to the vertical, and the output of the blower or air compressor 13 is a stream of air directed into the burner basket 14 behind the burner assembly or air heating means 24 as shown in the side elevation of FIG. 5.

The heater housing or basket 14 has an ignition port 47 in one side thereof as a convenient opening to the burner assembly 24 when the burners 34 therein are to be ignited. The housing 14 also has at the output end thereof a nozzle comprising, for example, an adjustable flap 26 carried on a hinge 27 to provide a variable orifice for the output stream of hot air as shown in FIG. 5.

A portable heater used for glazing compacted snow buildings, drying flat roofs prior to repair work and the like is shown in FIG. 2 and carries a burner assembly 24 in the heater housing 14 in a manner identical to that described with reference to FIG. 1. The exact position of the burner assembly 24 may be seen in the cutaway section of FIG. 5, and the position of the burner assembly 24 in the heater housing 14 in both FIGS. 1 and 2 is the same. The portable heater in FIG. 2 has a handle 48 carried by handle support brackets 49 and also has in one side thereof an ignition port 47. The blower 62 which forces the hot air from the burner assembly to the output of the basket 14 comprises a turbine wheel 61 rotatably mounted in a blower housing behind the burner assembly 24. The turbine wheel 61 is driven by air at high pressure and low volume supplied by air line 46 through a valve 51 to air nozzle 50 immediately adjacent to the turbine wheel 61. The turbine wheel 61 converts the air at high pressure and low volume to air at low pressure and high volume at the output of the blower and directs the low pressure air to the burner assembly 24 within the housing 14. The burner assembly 24 may be connected to a fuel line 22 having a needle valve 23 therein and connectable to a convenient propane supply.

Referring more in detail to the burner assembly common to both the portable heater in FIG. 2 and the mobile heater in FIG. 1, there is shown in FIG. 3 an enlarged sectional view of the burner assembly 24. This assembly includes a cylindrical and longitudinal pipe burner housing 31 having openings 38 and 39 in each end thereof enabling air at atmospheric pressure to be circulated within the housing 31. A cylindrical tube 32 carrying propane gas 33 is mounted within the burner housing 31 with its longitudinal axis substantially parallel to the longitudinal axis of the burner housing 31. The cylindrical tube 32 may be secured to housing 31 by a plurality of metal straps (not shown) and has spaced therealong a plurality of cylindrical burners 34 having threaded portions 41 and 42 at the outer portions thereof and threaded portion 43 at one inner portion thereof. The threaded portions 41 are frictionally engaged with threaded bores in the spaced cylindrical openings along the fuel tube 32, and the burners 34, having first and second diametersjSZ and 53, carry discharge nozzle 37 at the smaller diameter 53 thereof.

The burners 34 are screwed within the cylindrical heaters 35 and threadably engage said heaters in an opening 42 at one end thereof. The heaters 35, in addition to having an opening 42 at one end thereof to receive the burners 34, also have a pair of arcuate openings 36 therein. This pair of arcuate openings forms the second and third openings in one end of each of the heaters 35 and surrounds the burners 34 to enable air flow at atmospheric pressure to be evenly distributed within the heaters 35 upon combustion of propane gas therein. The heaters 35 are mounted within cylindrical openings spaced along the exterior of the cylindrical tube 31. These last-named openings 40 spaced along the burner housing 31 have cutout sections 54 in the periphery thereof to receive the cylindrical heaters 35 with a snug fit. Being clamped at 54, the heaters 35 are restrained against any vertical movement within the burner housing 31.

A preheater element 44 extending through the burner housing 31 and into a flame emanating from one of the burners 34 is aflixed to and inserted into the cylindrical tube 32 at a central portion 45 thereof.

Referring back to FIG. 1, the operation of the mobile snow melter will be hereinafter described. The outlet 21 in the propane supply tank has been positioned at the lower end thereof to insure an output of liquid rather than gaseous propane into the propane supply hose 22. The propane must be liquid in this portion of the hose since large volumes of gaseous propane would freeze in the supply hose immediately beyond the needle valve 23 where a pressure drop occurs in the flow of propane before reaching the burner assembly 24. Where liquid propane is used, the pressure drop within the needle valve 23 may still be suflicient to cause freezing in the hose 22 beyond the valve 23. However, means are provided as will be seen hereinafter to reduce initial freeze-up in fuel tube 32 due to the above pressure drop.

Upon ignition of the burners 34 by supplying a flame to the ignition port 47, there is initially an incomplete combustion within the cylindrical heaters 35 due to a substantial percentage liquid or solid propane at the output of nozzles 37 when the burners are first ignited. However, soon after a flame is directed from the nozzles 37, heat is radiated from the cylindrical heaters 35 to the fuel tube 32 and conducted to fuel tube 32 by a preheater means 44 having one end thereof positioned in a flame of one of the burners thus causing the liquid or solid propane 33 in the fuel tube 32 to vaporize. As this latter vaporization takes place, the combustion efliciency of the burners increases, and there is a draft of air at atmospheric pressure flowing from within the burner housing 31 through the arcuate opening 36 in one end of the cylindrical heaters 35 and evenly distributed to the output nozzle 37 of the cylindrical burners 34. Propane gas is known for its instability during combustion unless the air in which the combustion takes place is at or very near atmospheric pressure and at a relatively low velocity. The novel construction of the burner assembly including the arcuate openings in one end of the cylindrical heaters 35 provides the aforedescribed requirement during the combustion of the propane gas.

It will be observed that in both FIGS. 1 and 2 which carry the burner assembly 24 in the heater housings thereof, the air flow from the blower 31 is in the same direction as the flame emanating from the burners 34. This construction enables the pressure and velocity of the flame to augment the pressure and the velocity of the air in the direction of the output nozzle of housing 14 and thus provides a minimum of heat dissipation at the inner Walls of the burner basket. This construction allows working temperatures heretofore not practical, and

the burner basket may, for example, be constructed of thin galvanized iron.

By having the blower directed along the same line as the flame from the burners, air turbulence along either side of the burner assembly 24 is substantially eliminated, and the basket construction in combination with the plurality of burners mounted at one end thereof provides an even distribution of air flow, heat and pressure at the output nozzle comprising the adjustable flap 26.

Referring to the side elevation of the heater housing shown in FIG. 5, the nozzle assembly comprising the adjustable flap 26 and binge 27 may be adjustably mounted with respect to the basket 14 by means of slit 28 in one side of the end flange 30 within the basket 14 and a nut 29 threaded to a screw attached to these sides. The flange 30 is constructed integral with flap 26 and coplanar with the side of the basket 14 at the nozzle end thereof.

With this apparatus, a temperature of approximately 2600 F. may be obtained within the burner basket 14 and the burner assembly has an output capacity of 700,- 000 B.t.u.s per hour when four burners are used. Where a plurality of burners 34 are used in the burner assembly 24, the length of the burner basket may be shortened considerably over the length of the basket required for a burner assembly having a single burner, if the 700,000 B.t.u. per hour output capacity is to be attained under both conditions. The blower 31 may, for example, have a capacity of 2,500 cubic feet per minute for eflicient operation with the four burners 34 shown in FIG. 3 and such an arrangement will provide the required 700,000 B.t.u. per hour capacity output. By way of example only, the blower could employ a squirrel-cage type of motor in the 2 /2 to 3 horsepower range with a rotational velocity of 1750 rpm. For normal home use, a propane tank of approximately 20 lb. capacity would be sutficiently handy and could be easily replaced on the smaller home mobile units. However, for parking lots or larger areas a burner assembly having an output in the neighborhood of 650,000 to 1,000,000 B.t.u. per hour would be required, and a 60 lb. capacity propane type tank would be appropriate.

Many modifications may be made in the construction and operation of this invention; for example, a small economical gas turbine-driven compressor may be used instead of the gasoline driven engine compressor or blower described herein; the burner basket may be flexibly mounted to provide a means of raising and lowering the nozzle above the ground as a means of governing heat intensity in addition to the adjustable flap at the end of the burner basket; and various hydrocarbons besides propane may be used as the heating agent for the air.

The snow removing apparatus according to this invention as shown for the purpose of illustration, is relatively small in size for hand use as shown in FIG. 2 and for mobile use around the home for footways or garage driveways. It will be understood, however, that the principles of this invention may be embodied in large power propelled apparatus suitable for removing snow from large parking areas and for removing large masses of ice from various equipment used in the extreme cold sections of the world.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent of the United States is:

1. In a snow removal apparatus having a burner assembly for converting fuel into hot gas and an air blower means for producing a stream of air in the direction of snow to be removed and having its output focused on the hot gas for directing the hot gas onto said snow, the improvement comprising:

a hollow cylindrical burner housing having openings at both ends thereof for allowing air to be circulated therein; said housing positioned within the confines of said stream,

hollow tube means positioned within said burner housing and axially aligned longitudinally therewith for transmitting fuel to be ignited,

a plurality of burners positioned along said tube means in spaced openings therein for receiving said fuel, said burners having their discharge end focused in the direction of flow of said air stream, and

a plurality of hollow cylindrical heater means positioned along said burner housing in spaced openings therein and coaxial respectively with said burners,

said heater means having a first opening in one end thereof for receiving said burners at their discharge ends, said heater means further having a second opening in said one end thereof adjacent said first opening for allowing air flow therethrough at atmospheric pressure to said discharge end of said burners.

2. The combination of claim 1 which further includes preheater means having one end attached to said tube means and having its other end extending down stream from said burners whereby heat from a burner flame will be conducted through said preheater means to said tube means.

3. The combination in claim 2 wherein said fuel is propane in either liquid or solid form, said heat conducted by said preheater means to said tube means causes said liquid or solid propane in said tube means to change to its gaseous state.

4. The combination in claim 2 wherein said burners are threadedly engaged with said heater means at said first opening,

said burners further having nozzle means positioned within said discharge end thereof and extending axially within said heater means,

said heater means further having a third opening in said one end thereof adjacent said first opening, said second and third openings being arcuate and symmetrically disposed with respect to the periphery of said burner whereby air at atmospheric pressure may flow through said arcuate openings from said openings in said burner housing to said nozzle in said discharge end of said burners and be evenly dis-- tributed thereabout.

5. The combination of claim 1 wherein said air blower means comprises a turbine means mounted adjacent said burner housing,

means for supplying fuel to said tube means,

and means for supplying air at high pressure and low volume to said turbine means whereby said turbine means is driven to produce an air stream of low pressure and high volume having a direction of flow normal to the longitudinal axis of said burner housing.

6. The combination of claim 5 wherein said turbine means comprises a turbine wheel having its axis of rotation substantially parallel to the longitudinal axis of said burner housing.

7. The combination of claim 6 which further includes preheater means having one end thereof attached to said tube means and between said burners positioned therealong and having its other end extending down stream from said burners whereby heat from a burner flame will be conducted through said preheater means to said tube means.

8. Apparatus for the removal of snow comprising,

mobile supporting means,

air blower means mounted on said supporting means for directing a stream of air in the direction of snow to be removed,

means for driving said blower means mounted on said supporting means,

a heater housing having one end thereof attached to said blower means,

air heating means mounted within said heater housing and adjacent said air blower means, said air heating means including a plurality of fuel burners aligned in the direction of said air stream,

a hollow burner housing having openings at both ends thereof and positioned within the confines of said air stream,

a hollow tube means within said burner housing and aligned therewith for transmitting fuel to be ignited, said tube means having a plurality of openings spaced therealong to receive said burners,

a plurality of hollow cylindrical heater means positioned along said burner housing in spaced openings therein and substantially coaxial respectively with said burners,

said heater means having a first opening at one end thereof for receiving a discharge end of said fuel burners, said heater means further having a pair of arcuate openings at said one end surrounding said first opening for allowing air flow therethrough at atmospheric pressure to said discharge end of said burners.

9. The combination of claim 8 which further comprises preheater means having one end thereof attached to said tube means between said fuel burners positioned therealong and having its other end extending down stream from said burners into a flame emanating therefrom whereby said heat from a burner flame will be conducted through said preheater means to said tube means.

10. The combination of claim 9 wherein said burners are threadedly engaged with said heater means at said first opening,

said burners further having nozzle means positioned within said discharge end thereof and extending axially within said heater means, said fuel in said tube being liquid or solid propane whereby when heat is conducted to said tube by said predetermined heater means said liquid or solid propane changes to its gaseous state.

11. A fuel burner assembly adapted for use in a snow removal apparatus comprising:

a hollow burner housing having openings at both ends thereof,

hollow tube means positioned Within said burner housing and having its longitudinal axis aligned with the longitudinal axis of said burner housing for transmitting fuel to be ignited,

a plurality of burners positioned along said tube means in spaced openings therein for receiving said fuel,

a plurality of hollow heater means positioned along said burner housing in spaced openings therein and coaxial respectively with said burners,

said heater means having a first opening in one end thereof for receiving said burners at their discharge ends, said heater means further having a second opening in said one end adjacent said first opening for allowing air flow therethrough at atmospheric pressure to said discharge end of said burners.

12. The combination of claim 11 which further includes preheater means having one end attached to said tube means and having its other end extending down stream from said burners whereby heat from a burner flame will be conducted through said preheater means to said tube means.

13. The combination in claim 11 wherein said fuel is propane in either liquid or solid form, said heat conducted by said preheater means to said tube means causes said liquid or solid propane in said tube means to change to its gaseous state.

14. The combination in claim 11 wherein said burners are threadedly engaged with said heater means at said first opening,

said burners further having nozzle means positioned within said discharge end thereof and extending axially Within said heater means,

said heater means further having a third opening in said one end thereof adjacent said first opening, said second and third openings being areuate and symmetrically disposed with respect to the periphery of said burner whereby air at atmospheric pressure may flow through said arcuate openings from said openings in said burner housing to said nozzle in said discharge end of said burners and be evenly distributed thereabout.

References Cited by the Examiner UNITED STATES PATENTS 4/80 W'ells 15867 X 4/92 Steel 126-2712 4/39 Taber 126-2711 X 9/51 Wilson 126271.2 1/58 Zimmerman 126-2712 6/58 Davisson et al 126-271.2

FOREIGN PATENTS 1 1/24 Germany. 4/33 Germany.

JAMES W. WESTHAVER, Primary Examiner. 

1. IN A SNOW REMOVAL APPARATUS HAVING A BURNER ASSEMBLY FOR CONVERTING FUEL INTO HOT GAS AND AN AIR BLOWER MEANS FOR PRODUCING A STEAM OF AIR IN THE DIRECTION OF SNOW TO BE REMOVED AND HAVING ITS OUTPUT FOCUSED ON THE HOT GAS TO DIRECTING THE HOT GAS ONTO SAID SNOW, THE IMPROVEMENT COMPRISING: A HOLLOW CYLINDRICAL BURNER HOUSING HAVING OPENINGS AT BOTH ENDS THEREOF FOR ALLOWING AIR TO BE CIRCULATED THEREIN; SAID HOUSING POSITIONED WITHIN THE CONFINES OF SAID STREAM, HOLLOW TUBE MEANS POSITIONED WITHIN SAID BURNER HOUSING AND AXIALLY ALIGNED LONGITUDINALLY THEREWITH FOR TRANSMITTING FUEL TO BE IGNITED, A PLURALITY OF BURNERS POSITIONED ALONG SAID TUBE MEANS IN SPACED OPENINGS THEREIN FOR RECEIVING SAID FUEL, SAID BURNERS HAVING THEIR DISCHARGE END FOCUSED IN THE DIRECTION OF FLOW OF SAID AIR STREAM, AND A PLURALITY OF HOLLOW CYLINDRICAL HEATER MEANS POSITIONED ALONG SAID BURNER HOUSING IN SPACED OPENINGS THEREIN AND COAXIAL RESPECTIVELY WITH SAID BURNERS, SAID HEATER MEANS HAVING A FIRST OPENING IN ONE END THEREOF FOR RECEIVING SAID BURNERS AT THEIR DISCHARGE ENDS, SAID HEATER MEANS FURTHER HAVING A SECOND OPENING IN SAID ONE END THEREOF ADJACENT SAID FIRST OPENING FOR ALLOWING AIR FLOW THERETHROUGH AT ATMOSPHERIC PRESSURE TO SAID DISCHARGE END OF SAID BURNERS. 